Antarctic krill, a small yet long-lived crustacean, occupies a vital role in the Southern Ocean ecosystem. It forms a key prey item of many of the marine higher predators, particularly in the Scotia Sea in the Southwest Atlantic sector of the Southern Ocean. Krill is found in a patchy distribution throughout the Southern Ocean, with strong links to both the advective flow of the ocean and to the sea ice environment. In this talk I will give an overview of the research that is taking place at the British Antarctic Survey to determine the distribution of krill, with results from field studies and model analyses.